What Is the “ND Filter Shutter Speed Calculator”?

In landscape and night photography, long exposure (slow shutter) is an indispensable technique. However, when using high-density filters such as ND1000 or ND2000, it can become so dark that autofocus and exposure metering may not function properly.

This tool instantly calculates the exact shutter speed required after attaching an ND filter based on the proper exposure without the filter. It also supports fine adjustments when ISO sensitivity or the f-number is changed to match shooting conditions on site.

Shooting scenes where long exposure is especially useful

• Flowing waterfalls and streams: An exposure of a few seconds turns water into a silky texture (silky effect).
• Light trail photography: In night or twilight scenes, it captures car headlights and taillights as beautiful streaks of light.
• Smoothing waves on the sea or a lake: Long exposures of over a minute smooth the waves and create a dreamlike water surface.
• Removing crowds in daytime: By exposing for several minutes at tourist spots and similar locations, moving passersby can be blurred away and effectively removed.

Quick reference table for ND filter stops and multipliers

The number on an ND filter indicates how much the amount of light is reduced. Converted into stops (EV), it corresponds to the following:

• ND2: 1 stop (exposure time x2)
• ND4: 2 stops (exposure time x4)
• ND8: 3 stops (exposure time x8)
• ND16: 4 stops (exposure time x16)
• ND32: 5 stops (exposure time x32)
• ND64: 6 stops (exposure time x64)
• ND100: approx. 6.6 stops (exposure time approx. x100)
• ND400: approx. 8.6 stops (exposure time approx. x400)
• ND500: approx. 9.0 stops (exposure time approx. x500)
• ND1000: 10 stops (exposure time x1000)

Shooting advice

If the calculated result exceeds 30 seconds, many cameras can no longer shoot in normal mode. In that case, switch the camera setting to “BULB” or “Time” mode and use a remote release or timer function to take the shot. Also, mirrorless cameras and DSLRs are more likely to produce noise during long exposures, so consider using the “Long Exposure Noise Reduction” setting or adjusting ISO sensitivity as needed.